Melbourne - Japan's Kei Nishikori fought past a tough Australian challenge from Jordan Thompson to post a 6-4, 3-6, 7-6 (7/4) opening win at the Kooyong Classic on Wednesday.
The defending champion at the eight-man tune-up for the Australian Open needed just over two hours to earn the victory.
US Open finalist Nishikori, ranked fifth in the world, was forced to work hard in swirling winds at Kooyong Club.
"Conditions made it tough to play," said the 25-year-old Nishikori.
"It was difficult for me to be aggressive. But I played a good tiebreak and I'm happy to win today."
Nishikori came to Kooyong after a semi-final last weekend in Brisbane, where he lost to Canadian Milos Raonic in three tiebreak sets.
After winning the opening set thanks to a break in the first game, Nishikori's level slipped as the Australian world number 273 made his move in the second set, winning it via a break of serve in the fourth game.
The third set was halted for a short time due to a passing shower.
When the players returned Nishikori failed to serve out for victory at 5-3, the set eventually going to a tie-break after the Thompson saved a match point in the 12th game.
Nishikori took his first match point in the tie-break as the Australian double-faulted.
"I had a good start here last year," said Nishikori. "And I did well last season. I'm coming in with a lot of confidence.
"I've had good off-season training and hopefully I can have another good season.
"Jordan was playing well, especially in the second set, he was not missing much and going for his shots," he added.
Later matches see France's Gilles Simon facing Fernando Verdasco of Spain, Ukrainian Alexandr Dolgopolov against Serbian youngster Filip Krajinovic and Spanish veteran Feliciano Lopez versus Richard Gasquet of France.